Phytoplankton: characteristics, benefits and uses.
Phytoplankton are the base of the marine food web and play a crucial role in the marine reef aquarium ecosystem. These autotrophic microorganisms are able to transform inorganic nutrients dissolved in water into living biomass, playing a fundamental role as primary producers. In recent years, research on different phytoplankton species has intensified, revealing innovative applications in various sectors, including aquarium and aquaculture. In this article, we will focus on the importance of phytoplankton in aquarium, examining in particular the unique characteristics of some selected species.
Tetraselmis
Tetraselmis is a family of euryhaline algae found in both fresh and salt water. This alga, with its elongated cells (10-15 microns), is widely used for feeding filter feeders, bivalves and zooplankton. Characterized by a high concentration of proteins and an excellent amino acid profile, Tetraselmis is fast growing and effective in nutrient uptake, especially nitrates, making it useful for nutrient export and system stabilization.
It is particularly effective when used in combination with other algae species.
Synechococcus
Synechococcus is a family of planktonic cyanobacteria present in all seas and oceans, of which euryhaline and freshwater species are also known.
Very small in size (1-2 microns), and of an intense emerald green colour, it is practically unknown in aquaculture and other classic application sectors.
Synechococcus is characterized by a good presence of pigments such as phycocyanins and phycobilins and by a balanced composition, it can be used as food for zooplankton and filter feeders, which accept very small phytoplankton.
It has been brought to the fore in recent years for its ability to actively combat cyanobacteria, bacterial agglomerates and other algal growths in aquariums.
It is not yet clear whether the mechanism of action is based on metabolic competition or whether it involves the production of allopathic antagonist molecules, but its effectiveness in fighting infesting cyanobacteria has now been proven.
Also an excellent candidate for the export of nutrients and in particular of phosphorus, thanks to its ability to fix gaseous nitrogen, it can absorb the phosphate present in the tank even with a nitrate level close to zero.
Porphyridium
Porphyridium is a genus of microalgae with enormous application potential. These algae are known to produce numerous bioactive molecules, some of them with antimicrobial, antiviral, anti-inflammatory and immunostimulatory properties.
Porphyridium is effective in absorbing nitrogenous nutrients but at the same time produces exopolysaccharides which have demonstrated high efficacy in removing several heavy metals.
Thanks to these unique characteristics and its biochemical composition, we consider Porphyridium an ideal candidate for advanced integrative protocols.
Dunaliella
Dunaliella is a unicellular green algae, known for its tolerance to high salt concentrations. This algae produces beta carotene under stress conditions, an important carotenoid and precursor of vitamin A.
Dunaliella is effective at absorbing and metabolizing nutrients, especially nitrates, and is particularly suitable for use in carbon-dosed systems.
Its ability to produce carotenoids and other bioactive molecules makes it a valuable ingredient in the diet of zooplankton and filter feeders, contributing to their health and coloration.
It is also particularly effective when used in combination with other algae species.
Isochrysis
Isochrysis, a microalgae of the golden algae family, recognized for its remarkable nutritional properties and widely used in shellfish farming and professional aquaculture.
This small, spherical algae (about 6 microns in diameter) is known for its high content of lipids and essential fatty acids and is an excellent food for filter feeders, bivalve mollusks and zooplankton. Due to its ability to absorb and metabolize nutrients, it contributes significantly to nutrient export and system stabilization.
Furthermore, its ability to perform both photosynthesis (autotrophic metabolism) and heterotrophic/mixotrophic nutrition makes it particularly suitable in systems where bacterial proliferation is stimulated by carbon dosing.
Haematococcus
Haematococcus is a freshwater microalgae, famous for its ability to produce astaxanthin under stress, a powerful antioxidant and carotenoid pigment. This pigment, which protects the algae from oxidative stress caused by solar radiation, is responsible for the red color of many animal species that feed on it directly or indirectly.
The larger size of Haematococcus (about 20 microns) makes it ideal for feeding benthic, filter-feeding and zooplankton, carrying antioxidants and beneficial pigments.
Haematococcus does not have the ability to reproduce in the aquarium but is particularly rich in proteins, lipids and essential fatty acids, making it an excellent choice for dietary supplementation in marine aquariums.
Benefits and uses of phytoplankton
System Stability: Regular dosing of phytoplankton significantly contributes to maintaining stability in our reef ecosystem.
The constant presence of these microalgae helps reduce the levels of dissolved nutrients, improves water quality, counteracts the formation of unwanted algal and bacterial films, increases the number of filter-feeding organisms and their larvae.
When nutrient excesses or metabolic imbalances in the system occur, the dosage of different strains of phytoplankton is one of the first interventions we recommend, coupled with the BEA AEQUILIBRIUM bacterial protocol and a targeted dosage of BEA RESOLVE .
Biological control: Numerous species of phytoplankton have been shown to be effective in counteracting the growth of cyanobacteria, bacterial clumps and other unwanted algal blooms in aquariums, thanks to their competition for nutrients and the production of antimicrobial and antialgal compounds.
Our advice in case of unwanted bacterial or algal growth is to always vary the number of strains added as much as possible to enhance their effect ( BEA synecho Mix, BEA Black Pro and BEA Red Pro ).
Feeding for zooplankton and benthic organisms: Phytoplankton provide an essential food source for zooplankton and benthos, which in turn are essential for the diet of many corals, fish and invertebrates.
Additionally, phytoplankton supports the growth and health of benthic organisms, bivalves and other filter feeders, which help stabilize the system, reduce nutrients and provide a regular supply of live food to the system.
In systems where nutrient inputs must be reduced and “dirty” cannot be done, we always recommend replacing traditional foods with live phytoplankton and zooplankton.
Source of Bioactive Molecules: Numerous species of phytoplankton are known to produce bioactive compounds that are beneficial to aquatic organisms.
Several molecules produced by phytoplankton exhibit biological immunostimulatory activity and possess antimicrobial and antiviral properties.
These compounds strengthen the immune system of marine organisms and help maintain a low free bacterial load in the water and a healthy system microbiota.
Polyunsaturated fatty acids, such as EPA and DHA, are essential for the neurological and general health of marine organisms, enzymes produced by several species of phytoplankton improve the digestion and assimilation of nutrients.
Also important is the presence of antioxidants and photoprotective pigments, which offer protection from UV damage and help maintain the animals' vibrant coloration.
Conclusions
A quality phytoplankton dosage can provide tremendous benefits to the system, especially when fed regularly and with regular variation of strains.
Choosing the right species, integrating them into the diet and supplementation routine can make a substantial difference in the health and well-being of our guests and in general the health of the entire system. Phytoplankton supplementation is a practice that goes beyond simple feeding. It actively contributes to the stability and balance of the ecosystem, and is now established as a fundamental integration, in all advanced natural management techniques, at the base of BEA protocols.